Display screen or portion thereof with a graphical user interface of an electronic device



The FIGURE is a front view of a display screen or portion thereof with a graphical user interface of an electronic device.

The broken lines showing an electronic device display screen or portion thereof and elements of the graphical user interface represent environment and form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a graphical user interface of an electronic device, as shown and described. 